Process for continuous dyeing polyacrylonitrile textile material for a hydrophobic solvent dyebath

ABSTRACT

A process for dyeing textile material based on aromatic polyester fibers or acrylic fibers, wherein the textile material is impregnated with a solution containing at least one basic disperse dyestuff in an organic solvent and the dyestuff is fixed on the fiber by heat.

United States Patent Litzler et a1.

[ 1 May 16, 1972 PROCESS FOR CONTINUOUS DYEING POLYACRYLONITRILE TEXTILE MATERIAL FOR A HYDROPI-IOBIC SOLVENT DYEBATH Inventors: Alfred Litzler, ltingen; Visvanathan Ramanathan, Basel; Gert Hegar,

Schoenenbuch; Eugen Johann Koller, Oberwil; Branimir Milicevic, Riehen, all of Switzerland Assignee: Ciba Limited, Basel, Switzerland Filed: June 30, 1969 Appl. No.: 837,926

Foreign Application Priority Data July 1, 1968 Switzerland ..9807/68 US. Cl ..8/174, 8/177, 8/179 Int. Cl. ..D06p l/68 Field of Search ..8/172', 94, 83, 179, 174

OTHER PUBLICATIONS WAS White, Amer. Dyestuff Reporter, July 31, 1967, pp. 591- 597 TP890 A512. Chem. Eng. News 47, No. 15, p. 46 1969) TPl 1418.

Primary Examiner-George F. Lesmes Assistant Examiner-T. J. Herbert, Jr.

Attorney-Harry Goldsmith, Joseph G. Kolodny and Matio A. Monaco [5 7] ABSTRACT A process for dyeing textile material based on aromatic polyester fibers or acrylic fibers, wherein the textile material is impregnated with a solution containing at least one basic disperse dyestufi in an organic solvent and the dyestufi is fixed on the fiber by heat.

12 Claims, No Drawings PROCESS FOR CONTINUOUS DYEING POLYACRYLONITRILE TEXTILE MATERIAL FOR A HYDROPHOBIC SOLVENT DYEBATH The present invention is based on the observation that commercial textile material made of hydrophobic, fully synthetic fibers, filaments and yarns, woven and knitted fabrics made thereof, especially those based on acrylic fibers, can be dyed with good results by using a solution of the dyestuffs in an organic solvent in place of the conventional aqueous liquor in which the dyestuff is dispersed or dissolved.

An advantage of the use of an organic solvent as the dyeing medium is the substantially improved uniformity of the dyed material, especially its improved uniformity of the over the whole surface.

In view of the regulations concerning water pollution which are becoming ever stricter in many areas, the present process has the advantage that it results in less waste water.

Another advantage of the process of the invention over conventional dyeing with aqueous dyestuff dispersions is the possibility of using unconditioned disperse dyestuffs, whereas when dyeing by the conventional process from an aqueous dyebath it is always necessary to use conditioned dyestuff preparations to facilitate their dispersion in water.

The present invention provides a process for dyeing textile material based on hydrophobic polymers containing polar groups, ready for weaving, wherein the textile material is impregnated or printed, preferably padded, with a solution of at least one basic disperse dyestuff in at least one hydrophobic or in at least one hydrophilic solvent; the hydrophilic solvent concerned may contain up to 99 percent by weight of a hydrophobic component and must remain inert towards the textile material even at the dyeing temperature. To fix the dyestuff on the fiber the textile material is then subjected to a heat treatment at a temperature below the softening point of the fibrous material.

The present process is applicable to all fully synthetic, hydrophobic fibers containing polar groups, for example, to fibers of polyurethanes and polyamide fibers, for example, nylon 6, nylon 6.6 and nylon l l, fibers of aromatic polyesters, for example those of terephthalic acid and ethyleneglycol or l,4-dimethylolcyclohexane, or copolymers of terephthalic acid or isophthalic acid and ethyleneglycol, and especially acrylic or acrylonitrile fibers of polyacrylonitrile or of copolymers of acrylonitrile and other vinyl compounds, for example, acrylic esters, acrylamides, vinylpyridine, vinylchloride or vinylidene-chloride, copolymers of dicyanoethylene and vinyl acetate or of acrylonitrile block copolymers.

As solvents that must be extensively inert towards the fibers or filaments even at the dyeing temperature, that is to say, must not dissolve them, there may be mentioned, for example, the hydrophobic solvents that are at most only partially miscible with water, for example, acetophenone, cyclohexanol, benzyl alcohol, esters, for example, ethyl acetate, propylacetate, butyl acetate; hydrocarbons, for example, benzene, xylene or toluene and halogenated hydrocarbons, for example, carbon tetrachloride, chloroform, methylenechloride, trichloroethylene, perchloroethylene, trichloroethane, tetrachloroethane, dibromoethylene or chlorobenzene.

Water-miscible hydrophilic solvents, which boil preferably above 70 C, especially above 100 C but not at a temperature of greater than 220 C, form a preferred group of solvents, including for example aliphatic alcohols, for example, methanol, ethanol, n-propanol, isopropanol, ketones, for example, acetone, methylethylketone, cyclohexanone, ethers and acetals for example, diisopropyl ether, diphenylene oxide,

dioxane, tetrahydrofuran, glycerol formal and glycol formal,

also acetonitrile and pyridine, diacetone alcohol; furthermore high-boiling glycol derivatives, for example, ethyleneglycol mono-methyl, -ethyl and -butyl ethers and diethyleneglycolmono-methyl or -ethyl ether, thiodiglycol, polyethyleneglycols insofar as they are liquid at room temperature, ethylenecarbonate, 'y-butyrolactone and especially the group of watermiscible active solvents boiling at a temperature of greater than 120 C, for example, N,N-dimethylformamide, N,N- dimethylacetamide, bis-(dimethylamido)-methanephosphate, tris-(dimethylamido)-phosphate, N-methylpyrrolidone, 1,5- dimethylpyrrolidone, N,N-dimethylmethoxy acetamide, N,N,N',N-tetramethylurea, tetramethylenesulphone (sulpholan) and 3-methylsulpholan and dimethyl sulphoxide.

Among the hydrophilic solvents suitable for use in the present invention there are three preferred subgroups, namely (1) those which can dissolve linear, spinnable, fully synthetic polymers or polycondensates such, for example, as acrylonitrile polymers; (2) the group of the solvents miscible with water in any desired proportion and (3) the group of solvents free from hydroxyl groups. Any sulphur atom present in a solvent is preferably divalent or hexavalent.

When solvents capable of dissolving polyacrylonitrile are to be used for dyeing acrylic fibers, they must of course be admixed with a sufficient quantity of non-solvents to prevent dissolution of or damage to the acrylic fiber, or else the contact time in the continuously performed process is kept so short that the fiber swells at most only on its surface.

To prevent damage to the fiber, a simple small-scale test is made before proceeding to the dyeing operation to ascertain whether the fiber remains undissolved under the dyeing conditions in the presence of the solvent medium. Guide lines for the compatibility of solvents with different types of fibers will be found, for example, in the technical bulletin X-l56 of Du Pont de Nemours S.A., Geneva, Switzerland, on pages l4-l 5, of the edition of August 1962.

When a mixture of solvents is to be used, it may consist of two or more hydrophobic or of two or more hydrophilic constituents.

When a mixture of hydrophilic and hydrophobic solvents, which are compatible with each other, is to be used, it may contain up to 99 percent, preferably at least 50 percent by weight of the hydrophobic constituent. As a rule the hydrophobic solvent will boil at a lower temperature than the hydrophilic solvent. It is, however, also possible to use solvent pairs in which the hydrophobic share has a higher boiling point than the hydrophilic solvent.

The hydrophobic constituent of such solvent mixtures is preferably a chlorinated hydrocarbon, especially an aliphatic chlorinated hydrocarbon, for example, perchloroethylene or trichloroethylene. A preferred hydrophilic constituent is an N- alkylated amide of a lower fatty acid, for example, dimethylformamide, dimethylacetamide, N-methylpyrrolidone or tris- (dimethyl)-phosphoric acid triamide. A preferred mixing ratio of chlorocarbon hydrophilic constituent is 95 to 5 to 30 percent.

The basic disperse dyestuffs suitable for use in the present dyeing process are free from acid groups, and do not contain any quaternary nitrogen atoms. There are suitable, for example, dyestuffs in the following structural groups: monoazo, disazo and polyazo dyestuffs, anthraquinone, perinone, quinophthalone, nitroso, nitro, stilbene and methine dyestuffs, including the styryl, azamethine, polymethine and azostyryl dyestuffs.

It is also possible to use suitable types of dyestuffs, for example the following:

1. A20 dyestuffs (6) Porinone dyestuffs-Th0 mixtures of dyestuffs of the formula.

or the mixtures of dyestuffs-of the formula C \C=O l X 1'; V in which one X represents a group of the formula Nl-l and one X stands for a hydrogen atom.

7. Various dyestuffs Bis( 4-amino-meta-tolyl ortho-chlorophenyl)-methanecarbinol, the carbinol form of Rhodamine B (Color Index No. 45,170 B) ofthe formula COONa i0! IIIHCHa IL'HE-CHzCHr-Q O IIIH-C Ha The present process is preferably performed without addition of a dispersant, so that the resulting, dyed textile material is easier to clean, though, if desired, tensides may be added to the dyebath or padding liquor. I

Specially important tensides of a suitable nature are the following non-ionic compounds:

a. Ethers of polyhydroxy compounds, for example, polyoxyalkylated aliphatic alcohols, polyoxyalkylated polyols, polyoxyalkylated mercaptans and aliphatic amines, polyoxyalkylated alkylphenols and alkylnaphthols, polyoxyalkylated alkylarylmer'captans and alkylarylamines;

b. fatty acid esters of the ethyleneglycols and polyethyleneglycols, of propyleneglycol and butyleneglycol, of glycerol, of the polyglycerols and of pentaerythritol, as well as of sugar alcohols, for example, sorbitol, sorbitans and of saccharose;

c. N-hydroxyalkylcarbonamides, polyoxyalkylated carbonamides and sulphonamides.

Examples of tensides in these groups which may be advantageously used are: adducts of 8 mols of ethylene oxide with 1 mol of para-tertiaryoctylphenol, or of 15 or 6 mols of ethylene oxide with castor oil, or of 20 mols of ethylene oxide with the alcohol C l-l OH, ethylene oxide adducts with di-[aphenylethyl1-phenols, polyethylene oxide-tertiary dodecyl thioether, polyamine-polyglcol ether or adducts of 15 or 30 mols respectively of ethylene oxide with 1 'mol of the amine C, H ,,NHB2 or C l-l Nl-l Suitable mixtures with tensides have been proposed in German Specification No. 1,261,613.

Textile materials suitable for dyeing by the present process are primarily woven fabrics or suitable knitted fabrics or carpets of all kinds, the textile material being impregnated or printed, preferably padded, and then, to fix the dyestuff on the fiber, subjected to a heat treatment, preferably a dry heat treatment, at a temperature below the softening point of the fibrous material.

The treatment on the padder is carried out either at room temperature or with heating. After the dyestuff solution has been conveyed through the textile material, the latter is expressed to a content of impregnating solution of about 50 percent to 130 percent referred to the weight of the dry fibrous material.

If necessary, the impregnated or printed material leaving the padder or the printing machine respectively is either dried for a short time in a warm current of air (heated for example to 30 to C), or it is freed from the major portion of the adhering dyestuff solution in another manner, for example by centrifugation, or it is subjected to the fixation or thermofixation without drying. The thermofixation is carried out at a temperature of greater than C, preferably at a temperature of at least within the range of from to 240 C. At any rate, the temperature prevailing during the fixation must not reach the softening point of the fiber.

Thermofixation is carried out, for example, by steaming with saturated or unsaturated water vapor or preferably by a dry heat treatment, for example, with contact heat, by a treatment with high-frequency A.C. or by irradiation with infra-red rays.

The optimal thermofixing conditions, that prevent the fiber being damaged, are ascertained by a simple preliminary test.

it is also possible to fix the dyestuffs on the fiber by the socalled cold pad batch method, the padded and expressed fabric being reeled without previous drying, then if desired wrapped in a plastic foil and stored for some length of time, for example 24 hours, at room temperature, whereupon the fabric is unwrapped and dried to remove the solvent.

The following Examples illustrate the invention. Unless otherwise indicated, the parts and percentages in the Examples are by weight.

EXAMPLE 1 A fabric of polyacrylonitrile staple fibers (rlon regular) is padded with a cold solution of parts of the dyestuff of the formula in 1,000 parts of dimethylacetamide, then expressed to a weight increase of 67 percent referred to the weight of the fiber, dried in a current of air heated to 40 to 50 C, and then heat-set for 90 seconds at 200 C. A yellow dyeing is obtained which is fast to light and washing.

EXAMPLE 2 The procedure is as described in Example 1, except that Modacryl staple fiber fabric (Acrylan regular type 36) is used with a weight increase after expression of 104 percent. The resulting yellow dyeing is also fast to light and washing.

EXAMPLE'3 The procedure is as described in Example 1, except that a polyester staple fiber fabric (Dacron) with a weight increase of 60 percent after expression is used. The resulting dyeing is analogous to that described in Example 1.

EXAMPLE 4 Polyacrylonitrile staple fiber fabric is padded with a cold solution of 10 parts of the dyestuff of the formula in 1,000 parts of a mixture of 90 percent of perchloroethylene and 10 percent of dimethylacetamide, expressed to a weight increase of 103 percent, dried in a current of air heated at 40 to 50 -C and then heat-set for 90 seconds at 200 C. The resulting red-brown dyeing is fast to light and washing. I

EXAMPLE 5 Dyeing is performed as described in Example 4, but a polyester staple fiber fabric (Dacron) is used and expressed to a weight increase of 81 percent. The resulting red-brown dyeing is fast to light and washing.

EXAMPLE 6 Dyeing is carried out as described in Example 4, but the textile material dyed is a Modacryl staple fiber fabric (Acrylan regular type 36) the material being expressed to a weight increase of 164 percent. The resulting red-brown dyeing is fast to light and washing.

EXAMPLE 7 Dyeing is carried out as described in Example 6, but the textile material dyed is a polyamide staple fiber fabric (nylon 6.6)

and it is expressed to a weight increase of 92 percent. A redbrown dyeing is obtained which is fast to light and washing.

EXAMPLE 8 A polyacrylonitrile staple fiber fabric (Orlon) is padded with a cold solution of 10 parts of the dyestuff of the formula H ITYHCH:

EXAMPLE 9 A Modacryl staple fiber fabric (Acrylan regular type 36) is dyed as described in Example 8 and then expressed to a weight increase of 171 percent. The resulting dyeing corresponds to that obtained in Example 8.

EXAMPLE 10 A polyester staple fiber fabric (Dacron) is dyed as described in Example 8 and expressed to a weight increase of 86 percent. A result similar to that in Example 8 is obtained.

EXAMPLE 1 l A polyamide staple fiber fabric (nylon 6.6) is dyed as described in Example 8 and expressed to a weight increase of 100 percent. The result obtained is similar to that described in Example 8.

EXAMPLE 12 A woollen fabric is padded with a cold solution of 10 parts of the dyestuff used in Example 8 in 1,000 .parts' of perchloroethylene, expressed to a weight increase of 100 percent, dried in a current of air heated at 40 to 50 C and then heat-set for 90 seconds at 200- C. The fabric is then after treated for 30 minutes in an aqueous solution of 2 parts of an adduct of 9 mols of ethylene oxide with 1 mol of nonylphenol in 1,000 parts of boiling water, whereupon a brilliant blue dyeing develops which is fast to washing.

EXAMPLE 13 Dyeing is carried out as described in Example 4, except that tris-(dimethyl)-phosphoric acid triamide is used instead of dimethylacetamide. The resulting red-brown dyeing is fast to light and washing.

EXAMPLE 14 Polyester webbing is dyed as described in Example 13. The webbing was dyed red-brown shades fast to light and washing.

We claim:

1. A process for the continuous dyeing of textile material comprising polymers and copolymers of acrylonitrile which comprises padding said textile with a solution comprising at least one basic disperse dyestuff in a hydrophobic solvent which is inert towards the textile and thereafter heating the dyed textile at a temperature of from C to below the softening point of the textile fibers to fix the dye.

2. A process as claimed in claim 1, wherein the dyestuff is fixed on the fiber by subjecting the impregnated textile material to a dry-heat treatment.

3. A process as claimed in claim 1, wherein the fabric is dried before the dyestuff is fixed.

4. A process as claimed in claim 3, wherein the solvent is expelled by evaporation.

9. A process as claimed in claim 8, wherein a dyestuff is used that contains a monoor di-alkylated amino group.

10. A process as claimed in claim 7, wherein a dyestufi is used that contains a cyclically bound amino group.

11. A process as claimed in claim 10, wherein a dyestuff is used that contains an aromatically bound amino group.

12. A process as claimed in claim 11, wherein a dyestufiis used that contains a pyridine ring.

PO-ww 1 UNITED STATES PATENT OFFICE,

CERTIFICATE OF CORRECTIGN Patent No. 3,663,161 Dated May 16, 1972 Inventor(s) Alfred Litzler et a1 It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 1, [73] Assignee should read:

CIBA-GEIGY AG Signed and sealed this 19th day of March 1974.

(SEAL) Attest:

EDWARD M.FLETCHER,'JR. C. MARSHALL DANN Attesting Officer Commissioner of Patents 

2. A process as claimed in claim 1, wherein the dyestuff is fixed on the fiber by subjecting the impregnated textile material to a dry-heat treatment.
 3. A process as claimed in claim 1, wherein the fabric is dried before the dyestuff is fixed.
 4. A process as claimed in claim 3, wherein the solvent is expelled by evaporation.
 5. A process as claimed in claim 1, wherein the only solvent used is a chlorinated hydrocarbon.
 6. A process as claimed in claim 5, wherein the solvent used is perchloroethylene.
 7. A process as claimed in claim 1, wherein the dyestuff used is a disperse dyestuff that contains at least one non-quaternary amino group and is substantially insoluble in water at a temperature of 80* C.
 8. A process as claimed in claim 7, wherein a dyestuff is used that contains a primary amino group.
 9. A process as claimed in claim 8, wherein a dyestuff is used that contains a mono- or di-alkylated amino group.
 10. A process as claimed in claim 7, wherein a dyestuff is used that contains a cyclically bound amino group.
 11. A process as claimed in claim 10, wherein a dyestuff is used that contains an aromatically bound amino group.
 12. A process as claimed in claim 11, wherein a dyestuff is used that contains a pyridine ring. 